Nucleic Acids Res. 13:4739-4749 (1985) describes new Type I interferons which differ substantially from the previously known .alpha.- and .beta.-interferons with regard to their structure and antigenic properties. This new class of interferon has been designated IFN-omega.
The object of EP-A-0.236.920 (published Sep. 16, 1987) makes it possible to substantially improve the purification of IFN-omega using new monoclonal antibodies, e.g., the new monoclonal antibody OMG-2. These antibodies, however, show specificity for both IFN-.alpha. and IFN-omega. It is not possible to conduct an immunoassay for detecting IFN-omega using these antibodies because the level of IFN-omega-specific antibodies in the polyclonal immunoglobulin used as the coating antibody is too low. Moreover, such a test would not be specific for IFN-omega because both the polyclonal and monoclonal antibodies recognize IFN-.alpha..
The detection and quantification of IFN-omega has thus been carried out exclusively via biological testing, for example, by measurement of antiviral activity. Although these detection methods are generally very sensitive, they are time-consuming, laborious and imprecise.
Thus, an immunoassay, such as an ELISA or IRMA test, is needed which could simply, quickly and accurately detect and quantify IFN-omega. Since IFN-omega is present as a monomer in solution, this type of immunoassay would require at least two antibodies capable of recognizing different epitopes of the IFN molecule. For such an assay, the use of monoclonal antibodies would not be essential but would have numerous advantages over antisera.